// async_attach.h
// custom attachments for frequency controls
// changes are withheld until confirmed

#pragma once
#include "JuceHeader.h"

struct AsyncAttachmentSource : juce::AudioProcessorValueTreeState::Listener
{
    friend struct AsyncAttachment;
    AsyncAttachmentSource (juce::AudioProcessorValueTreeState& state, const juce::String& id);
    ~AsyncAttachmentSource() { state_.removeParameterListener (paramID_, this); }
    auto lastValue() const   { return lastValue_; }
    auto parameter() const   { return state_.getParameter (paramID_); }
    void beginGesture()      { if (notifyGesture) notifyGesture (true); }
    void endGesture()        { if (notifyGesture) notifyGesture (false); }
    void confirmValue (float value, bool setParameter);
    void confirmGesture (bool starting);
    std::function<void (float, bool)> notifyValue;
    std::function<void (bool)> notifyGesture;
private:
    void parameterChanged (const juce::String&, float value) override;
    juce::AudioProcessorValueTreeState& state_;
    const juce::String paramID_;
    std::vector<AsyncAttachment*> attachments_;
    float lastValue_{};
    bool ignoreCallbacks_{};
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AsyncAttachmentSource)
};

struct AsyncAttachment
{
    AsyncAttachment (AsyncAttachmentSource& src) : source{ src } { src.attachments_.push_back (this); }
    virtual ~AsyncAttachment();
    virtual void setLastValue() = 0;
    void valueChanged (float newValue);
    AsyncAttachmentSource& source;
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AsyncAttachment)
};

struct AsyncSliderAttachment : juce::Slider::Listener, private AsyncAttachment
{
    AsyncSliderAttachment (AsyncAttachmentSource& src, juce::Slider& slider);
    ~AsyncSliderAttachment()                         { slider_.removeListener (this); }
private:
    void sliderDragStarted (juce::Slider*) override  { source.beginGesture(); }
    void sliderDragEnded (juce::Slider*) override    { source.endGesture(); }
    void sliderValueChanged (juce::Slider*) override { valueChanged (float (slider_.getValue())); }
    void setLastValue() override                     { slider_.setValue (source.lastValue(), juce::sendNotificationSync); }
    juce::Slider& slider_;
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AsyncSliderAttachment)
};